Cotton incorporated Poly(lactic acid)/thermoplastic Starch Based Composites Used as Flexible Packing for Short Shelf Life Products

Biocomposites have gained attention in the packaging industry due to their potential as sustainable alternatives to conventional synthetic materials. In this study, novel cotton incorporated poly(lactic acid)/thermoplastic starch biocomposites were developed for packaging applications using in short shelf life products the extrusion method. Pelletized samples obtained by extrusion were stamped from plates obtained by compression and were characterized through measurement of density, hardness, contact angle and water absorption, as well as Fourier transform infrared spectroscopy (FTIR), thermal analysis and scanning electron microscopy (SEM). No significant changes in the density results were observed. A slight increase in the hardness of formulations in relation to the PLA was associated with the presence of cotton fiber in biocomposites. The FTIR results revealed physical interaction of PLA, TPS and cotton fiber. By DSC analysis, for all formulations the melting exhibited only one peak, suggesting good homogeneity and interaction among the components, as observed by TG/DTG results, and corroborating SEM analysis. The biocomposite PLA/TPS/Cotton 85/10/5 wt.% displayed greater increase in water absorption than both 95/5/0 and 90/5/5 wt.% formulations, which can be attributed to the increase in starch proportion, confirming the contact angle results. The hydrophilic tendency corroborated the biodegradation process in the packaging end-of-life.

Keywords:
PLA; TPS; Water Absorption; Thermal Properties; Mechanical Properties